Intrauterine devices (IUDs) are an effective form of contraception, but only about 3.4% of women in the US report using them. Women must often wait for their menses to start, or for results of screening for sexually transmitted infections (STIs), before their doctors will place IUDs for them. This is not the case with other birth control methods. Researchers know that it is safe to start oral contraceptive pills, transdermal patches or vaginal rings on the same day of a doctor's visit. In the investigators clinical practice, the investigators often place IUDs on the same day of a woman's visit, but outcomes have not been formally assessed.